Time¶

Overview¶

Schedulers maintain Clock objects to track time. The current time in relation to a Scheduler is stored in Scheduler.clock.time or Scheduler.clock.simple_time

class psyneulink.core.scheduling.time.TimeScale¶

Represents divisions of time used by the Scheduler, Conditions, and the time_scale argument of a Composition’s run method.

The values of TimeScale are defined as follows (in order of increasingly coarse granularity):

TIME_STEP¶: the nuclear unit of time, corresponding to the execution of all Mechanisms allowed to execute from a single consideration_set of a Scheduler, and which are considered to have executed simultaneously.

PASS¶: a full iteration through all of the consideration_sets in a Scheduler's consideration_queue, consisting of one or more TIME_STEPs, over which every Component specified to a Scheduler is considered for execution at least once.

TRIAL¶: an open-ended unit of time consisting of all action that occurs within the scope of a single input to a Composition.

RUN¶: the scope of a call to the run method of a Composition, consisting of one or more TRIALs.

LIFE¶: the scope of time since the creation of an object.

classmethod get_parent(time_scale)¶

Returns:	the TimeScale one level wider in scope than time_scale
Return type:	`TimeScale`

classmethod get_child(time_scale)¶

Returns:	the TimeScale one level smaller in scope than time_scale
Return type:	`TimeScale`

class psyneulink.core.scheduling.time.Clock¶

Stores a history of TimeScales that have occurred, and keep track of a current Time. Used in relation to a Scheduler

history¶: TimeHistoryTree – a root TimeHistoryTree associated with this Clock

get_total_times_relative(query_time_scale, base_time_scale, base_index=None)¶

Convenience simplified wrapper for TimeHistoryTree.get_total_times_relative

Parameters:	query_time_scale (`TimeScale`) – the unit of time whose number of ticks to be returned base_time_scale (`TimeScale`) – the unit of time over which the number of query_time_scale ticks should be returned base_index (int) – the base_indexth base_time_scale over which the number of query_time_scale ticks should be returned
Returns:	the number of query_time_scale s that have occurred during the scope of the base_index th base_time_scale
Return type:	int

get_time_by_time_scale(time_scale)¶

Parameters:	time_scale (`TimeScale`) –
Returns:	the current value of the time unit corresponding to time_scale for this Clock
Return type:	int

time¶: the current time – Time

simple_time¶: the current time in simple format – SimpleTime

previous_time¶: the time that has occurred last – Time

class psyneulink.core.scheduling.time.Time(time_step=0, pass_=0, trial=0, run=0, life=0)¶

Represents an instance of time, having values for each TimeScale

life¶: int : 0 – the TimeScale.LIFE value

run¶: int : 0 – the TimeScale.RUN value

trial¶: int : 0 – the TimeScale.TRIAL value

pass_¶: int : 0 – the TimeScale.PASS value

time_step¶: int : 0 – the TimeScale.TIME_STEP value

class psyneulink.core.scheduling.time.SimpleTime(run=0, trial=0, time_step=0)¶: A subset class of Time, used to provide simple access to only run, trial, and time_step

class psyneulink.core.scheduling.time.TimeHistoryTree(time_scale=<TimeScale.LIFE: 4>, max_depth=<TimeScale.TRIAL: 2>, index=0, parent=None, enable_current_time=True)¶

A tree object that stores a history of time that has occurred at various TimeScales, typically used in conjunction with a Clock

time_scale¶: TimeScale : TimeScale.LIFE – the TimeScale unit this tree/node represents

child_time_scale¶: TimeScale : TimeScale.RUN – the TimeScale unit for this tree’s children

children¶: list[TimeHistoryTree] – an ordered list of this tree’s children

max_depth¶: TimeScale : TimeScale.TRIAL – the finest grain TimeScale that should be created as a subtree Setting this value lower allows for more precise measurements (by default, you cannot query the number of TimeScale.TIME_STEPs in a certain TimeScale.PASS), but this may use a large amount of memory in large simulations

index¶: int – the index this tree has in its parent’s children list

parent¶: TimeHistoryTree : None – the parent node of this tree, if it exists. None represents no parent (i.e. root node)

previous_time¶: Time – a Time object that represents the last time that has occurred in the tree

current_time¶: Time – a Time object that represents the current time in the tree

total_times¶: dict{TimeScale: int} – stores the total number of units of TimeScales that have occurred over this tree’s scope. Only contains entries for TimeScales of finer grain than time_scale

Parameters:	enable_current_time (bool : True) – sets this tree to maintain a Time object. If this tree is not a root (i.e. time_scale is `TimeScale.LIFE`)

increment_time(time_scale)¶

Increases this tree’s current_time by one time_scale

Parameters:	time_scale (`TimeScale`) – the unit of time to increment

get_total_times_relative(query_time_scale, base_indices=None)¶

Parameters:	query_time_scale (`TimeScale`) – the `TimeScale` of units to be returned base_indices (dict{`TimeScale`: int}) – a dictionary specifying what scope of time query_time_scale is over. e.g. base_indices = {TimeScale.RUN: 1, TimeScale.TRIAL: 5} gives the number of query_time_scales that have occurred in the 5th `TRIAL` of the 1st `RUN`. If an entry for a `TimeScale` is not specified but is coarser than query_time_scale, the latest value for that entry will be used
Returns:	the number of units of query_time_scale that have occurred within the scope of time specified by base_indices
Return type:	int